1. Field of the Invention
The present invention relates to an image processing system and, more particularly, to an image processing system which performs image processing such as image formation based on an image signal output from an image reader.
2. Related Background Art
Various techniques have been proposed for image processing such as image formation based on an image signal obtained by photoelectrically reading an image. In most such techniques, the output unit which outputs the image signal and the image forming unit have a one-to-one correspondence. A technique may be proposed to form images at a plurality of image forming units based on an image signal output from a single output unit. However, this cannot be satisfactorily performed by simple electrical connections. That is, proper control and display must be performed. In addition, the operation procedure may become complex, which is a problem to the user.
When a plurality of images are formed at a plurality of image forming units, a required number of images can be formed within a time period far shorter than that required for a single image forming unit. However, when a number of images obtained by dividing a total number of images to be formed by the number of available image forming units is assigned to each image forming unit, if the respective image forming units have different functions and the like, the total image forming time is not effectively shortened.
If a plurality of image forming units constituting an image processing system have different functions (e.g., both or two-side copying print speed, collation function and the like), the operator must select and operate only those units which are suitable for the desired image formation mode.
When a plurality of images are formed by a plurality of image forming units, the total image formation time can be reduced, as compared to that required for a signal image forming unit which is to form the same number of images. Before,the operator starts any copy operation, he selects the proper image forming units and estimates the image formation time. In this connection, if one or more units selected by the operator have failed and cannot serve, the load assigned to the failed unit may be automatically assigned to another unit. When this technique is adopted, however, the resultant image formation time may be often prolonged beyond the initial time estimation. In addition, in some special image formation modes, such automatic reassignment may result in some problems.